Maximum safe working temperature for fireclay bricks is about __________ °C.
Maximum safe working temperature for fireclay bricks is about __________ °C.
Rotary kilns meant for calcination of limestone are lined with chrome magnesite in __________ zone.
Rotary kilns meant for calcination of limestone are lined with chrome magnesite in __________ zone.
Which of the following is not an acidic refractory?
Which of the following is not an acidic refractory?
Porosity of fireclay refractories is __________ percent.
Porosity of fireclay refractories is __________ percent.
Maximum water percentage in refractory mix meant for hand moulding may be as high as __________ percent.
Maximum water percentage in refractory mix meant for hand moulding may be as high as __________ percent.
Fireclay bricks is not used for lining the
Fireclay bricks is not used for lining the
__________ bricks are used in the burning zone of a cement rotary kiln.
__________ bricks are used in the burning zone of a cement rotary kiln.
Basic bricks are not made of
Basic bricks are not made of
Refractory bricks having lower porosity have
Refractory bricks having lower porosity have
PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.
PCE value (Segar cone) of superduty refractories is more than 33, which is equivalent to a temperature of __________ °C.
__________ is the measure of the strength of refractory under the combined effect of temperature & load.
__________ is the measure of the strength of refractory under the combined effect of temperature & load.
Hot blast main (carrying air at 1000°C) in blast furnace are lined with __________ bricks.
Hot blast main (carrying air at 1000°C) in blast furnace are lined with __________ bricks.
Test piece for determination of RUL of a refractory is heated in a/an
Test piece for determination of RUL of a refractory is heated in a/an
Mixing of ground refractory material and water is done in a __________ mill.
Mixing of ground refractory material and water is done in a __________ mill.
Silica bricks are never used for lining the
Silica bricks are never used for lining the
Fusion point of a basic refractory material is
Fusion point of a basic refractory material is
Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.
Lower wall courses of soaking pits are made of __________ bricks to avoid the action of molten slag & scale.
Presence of MgO in alumino-silicate refractories __________ its refractoriness.
Presence of MgO in alumino-silicate refractories __________ its refractoriness.
Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be
Furnace atmosphere for softening temperature determination of refractories (in which segar cones are placed) should be
Which property of refractories is the most important for top section of the blast furnace?
Which property of refractories is the most important for top section of the blast furnace?
Firing temperature of magnesite bricks is about __________ °C.
Firing temperature of magnesite bricks is about __________ °C.
Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.
Pyrometric cone equivalent (PCE) value (Segar cone) of 'superduty refractories' is more than 33 which corresponds to a temperature of __________ °C.
Which is not an acidic refractory?
Which is not an acidic refractory?
Insulating refractories should have
Insulating refractories should have
High thermal conductivity of a refractory material is not important, when it is to be used in the
High thermal conductivity of a refractory material is not important, when it is to be used in the
Roof of a basic open hearth furnace is lined with __________ bricks.
Roof of a basic open hearth furnace is lined with __________ bricks.
Hot face insulating linings of high purity alumina fused mullite are used, where
Hot face insulating linings of high purity alumina fused mullite are used, where
Which is not a natural insulating material?
Which is not a natural insulating material?
Alumina-graphite bricks are used for lining the
Alumina-graphite bricks are used for lining the
Lower part of hot metal mixer are lined with __________ bricks.
Lower part of hot metal mixer are lined with __________ bricks.
Fusion point of an acidic refractory material is
Fusion point of an acidic refractory material is
Magnesite refractories are generally not used in the
Magnesite refractories are generally not used in the
An ideal refractory should have high
An ideal refractory should have high
Thermal conductivity of refractory bricks
Thermal conductivity of refractory bricks
Cold crushing strength of a refractory does not depend upon its
Cold crushing strength of a refractory does not depend upon its
Periclase refractory contains mainly
Periclase refractory contains mainly
Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the
Cermets are combination of ceramic and metallic materials due to which they have high strength & resistance to high temperature. Cermets are used in the
Hot metal runner in blast furnace are lined with __________ bricks.
Hot metal runner in blast furnace are lined with __________ bricks.
Spalling resistance of a refractory can not be increased by
Spalling resistance of a refractory can not be increased by
Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for __________ bricks.
Refractoriness under loads (RUL) is quite close to the fusion temperature (PCE) for __________ bricks.
Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as __________ percent.
Maximum shrinkage in volume occurring during burning/firing of dried refractories may be as high as __________ percent.
Carbon bricks are not used in the lining of the
Carbon bricks are not used in the lining of the
Magnesite chrome bricks are used in the
Magnesite chrome bricks are used in the
Silica refractories are not used in
Silica refractories are not used in
Which is the stable form of silica between 1470°C and the melting point 1713°C ?
Which is the stable form of silica between 1470°C and the melting point 1713°C ?
Which one contains maximum percentage of Al2O₃ ?
Which one contains maximum percentage of Al2O₃ ?
Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
Thoria is an expensive refractory material and is radioactive in nature. Thorium oxide is used in the manufacture of
Which of the following is not a high alumina refractory material?
Which of the following is not a high alumina refractory material?
__________ is not a single oxiderefractory.
__________ is not a single oxiderefractory.
Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.
Refractoriness of a typical silica brick corresponds to Segar cone number, '32', which is equivalent to a temperature of __________ °C.
High alumina refractories are used in the
High alumina refractories are used in the
Porosity of silica bricks varies from __________ percent.
Porosity of silica bricks varies from __________ percent.
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of
Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
Capacity of a refractory brick to withstand-sudden changes in temperature is denoted by the property called
Vacuum steel degassing units are lined with
Vacuum steel degassing units are lined with
Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as __________ percent.
Pure bauxite is the best raw material for the manufacture of high alumina refractories, in which maximum alumina content can be as high as __________ percent.
In panel test for spalling resistance, the average face temperature of panel assembly is maintained at __________ °C for 24 hours.
In panel test for spalling resistance, the average face temperature of panel assembly is maintained at __________ °C for 24 hours.
An indication of degree of firing in silica brick is its
An indication of degree of firing in silica brick is its
Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks.
Slide gates in teeming laddie used for steel pouring in ingot moulds is lined with __________ bricks.
Outer combustion chamber of blast furnace stove is lined with __________ bricks.
Outer combustion chamber of blast furnace stove is lined with __________ bricks.
Permeability of bricks is a measure of the
Permeability of bricks is a measure of the
Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory
Dry mix hydraulic compositions of refractory aggregates with suitable bonding materials are called refractory
Semi-silica bricks compared to silica bricks have
Semi-silica bricks compared to silica bricks have
Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity).
Except __________ , all other refractories are bad conductors of electricity (i.e, have low electrical conductivity).
Bauxite calcining rotary kilns are lined with __________ bricks.
Bauxite calcining rotary kilns are lined with __________ bricks.
Hollow refractory bricks are made by
Hollow refractory bricks are made by
Addition of zircon to silica refractory brick improves its
Addition of zircon to silica refractory brick improves its
Chemically, mullite refractories is
Chemically, mullite refractories is
Which is required in an insulating refractory?
Which is required in an insulating refractory?
Roof of a basic electric furnace is made of __________ bricks.
Roof of a basic electric furnace is made of __________ bricks.
Magnesite bricks have poor resistance to attack by __________ slag.
Magnesite bricks have poor resistance to attack by __________ slag.
Which of the following bricks has the most close values of RUL and PCE?
Which of the following bricks has the most close values of RUL and PCE?
Thermal spalling mainly occurs during __________ of furnaces.
Thermal spalling mainly occurs during __________ of furnaces.
Highest melting (m.p = 3070°C) oxide refractory is
Highest melting (m.p = 3070°C) oxide refractory is
With increase in the alumina content in firebricks, its fusion point (refractoriness)
With increase in the alumina content in firebricks, its fusion point (refractoriness)
Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the
Upper portion of hot metal mixer are lined with mullite bricks, which helps in resisting the
Which is the stable form of silica upto 1470°C ?
Which is the stable form of silica upto 1470°C ?
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm² . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm² .
Cold crushing strength of ordinary fireclay brick is about 950 kg/cm² . On exposure to a temperature of about 1500°C, its crushing strength may come down to as low as __________ kg/cm² .
Which is the stable form of silica below 870°C ?
Which is the stable form of silica below 870°C ?
Chromite refractories are
Chromite refractories are
Cold crushing strength of refractories depends upon its
Cold crushing strength of refractories depends upon its
Which of the following is not a neutral refractory?
Which of the following is not a neutral refractory?
Conversion of silica mineral to cristobalite is accompanied by reduction in its
Conversion of silica mineral to cristobalite is accompanied by reduction in its
Zirconia refractories are not used in
Zirconia refractories are not used in
Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.
Most Cermets, which normally have high thermal conductivity and high thermal shock resistance, comprises of ceramic & metallic components of __________ percent respectively.
Thermal diffusivity of a refractory brick is high, when its __________ is high.
Thermal diffusivity of a refractory brick is high, when its __________ is high.
Maximum alumina content in high alumina refractory can be as high as __________ percent.
Maximum alumina content in high alumina refractory can be as high as __________ percent.
Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material?
Silica bricks are attacked by basic slags at high temperature. Which of the following is not used solely as a binding material?
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of __________ °C.
Which brick undergoes maximum shrinkage on drying?
Which brick undergoes maximum shrinkage on drying?
Colour of fireclay bricks is
Colour of fireclay bricks is
Chrome magnesite bricks are
Chrome magnesite bricks are
Magnesite refractories have low resistance to
Magnesite refractories have low resistance to
Carbon refractory blocks
Carbon refractory blocks
Carbon refractories
Carbon refractories
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?
Which property is important for bricks used in the combustion chamber & dome of blast furnace stoves?
Which is not a basic refractory?
Which is not a basic refractory?
__________ bricks should not be used in oxidising atmosphere.
__________ bricks should not be used in oxidising atmosphere.
